The present invention relates to an apparatus for rupturing a sealed, frangible container, such as a glass ampoule of the type used in a biological tester.
Hermetically sealed glass ampoules are widely used, particularly in the health care industry, to hold fluids that must be protected against contamination until they are ready for use. In particular, such ampoules are often used in biological indicating systems in which it is desirable to provide immediate and massive contact of a fluid contained in an ampoule with an external item. In one commonly used method of testing sterilizers, for example, a piece of filter paper having standardized biological spores of a strain sufficiently resistant to the sterilization medium are placed on a carrier (such as a piece of filter paper called a "spore strip" or "spore dot") which is exposed to the sterilization process being tested. Then the "sterilized" strip is exposed to a large amount of fluid nutrient. Sterilization of the standardized spore strain insures sterilization of bacterial strains in the chamber load, while survival of the standardized spore strain indicates unsatisfactory sterilization of the load.
Survival of the spores subsequent to the sterilization process is typically determined by mixing a test solution consisting of a nutrient growth medium containing a pH indicator with the spores and incubating the culture for growth. In spore fermentation, for example, glucose contained in the growth medium is utilized by viable spores, and pyruvic acid is produced as a by-product. Pyruvic acid lowers the pH of the test solution, thereby causing the pH indicator in the solution to change color. If there are no viable spores following sterilization, the pH (and thus the color) of the test solution remains essentially unchanged.
The immediate and massive outflow of the nutrient containing fluid from the ampoule to conduct the procedure described above has been described heretofore in U.S. Pat. Nos. 3,440,144, 3,661,717, and 4,304,869. While the methods and apparatus described therein are effective to provide the desired immediate outflow of the contents of the ampoule, some of the techniques described therein pose the risk of injury to the operator as well as the possibility of contamination. Also, those methods do not provide a simple apparatus for effectively mixing the nutrient fluid.